Such a saddle-ridden type fuel cell vehicle is disclosed, for example, in Patent Document 1 as described below. In the saddle-ridden type fuel cell vehicle, a handle and a steerable wheel are provided on a front portion of a body frame, a driving wheel is provided on a rear portion of the body frame via a swingable arm, and also a motor for driving the driving wheel is provided on the swingable arm. Also, a seat is provided on an upper side of the middle portion of the body frame in a front and rear direction thereof and a fuel cell for supplying an electric power to the motor is provided on an upper side of the rear portion of the body frame. In addition, a fuel tank for storing a fuel for the fuel cell is provided on a lower side of the middle portion of the body frame in the front and rear direction, and a tank valve (valve unit) for controlling supplying of the fuel from the fuel tank to the fuel cell is provided behind the fuel tank on the lower side of the middle portion of the body frame in the front and rear direction.
Also, in the saddle-ridden type fuel cell vehicle described in Patent Document 1, the fuel tank has a generally cylindrical exterior shape and is arranged so that an axis thereof is laid down to extend along the front and rear direction of the vehicle. Further, the body frame of the saddle-ridden type fuel cell vehicle includes a pair of right and left upper frames extending in the front and rear direction and a pair of right and left lower frames positioned below the upper frames and extending in the front and rear direction. The fuel tank is arranged in a center tunnel region encircled by the upper frames and the lower frames and is supported on the upper frames and the lower frames by a pair of tank bands (ring-shaped clamps). In addition, a guard frame is provided below a rear portion of the fuel tank and below the tank valve. The guard frame is installed between the pair of right and left lower frames.
Upon a side collision, a load is exerted on the saddle-ridden type fuel cell from a lateral side thereof. The upper frames and the lower frames encircling the fuel tank receive the load exerted from the lateral side to inhibit the load from being exerted on the fuel tank, thereby protecting the fuel tank.
In addition, upon running, a stone on a road is likely to be bounced and hit against a lower portion of the vehicle, or a protrusion of uneven road surface is likely to hit against the lower portion of the vehicle. The guard frame provided below the tank valve receives the bounced stone or the protrusion of the road surface to inhibit the bounced stone or the protrusion of the road surface from hitting against the tank valve, thereby protecting the tank valve.
Meanwhile, in Patent Document 1, it is mentioned that when the fuel tank is mounted on the saddle-ridden type fuel cell vehicle, the fuel tank can be mounted into the center tunnel region by causing the fuel tank to pass between the pair of lower frames from the lower side thereof, and as a result, maintenance thereof is enhanced.
Further, in the saddle-ridden type fuel cell vehicle described in Patent Document 1, the fuel tank is fixed on the upper frames and the lower frames by the tank band after the fuel tank is mounted into the center tunnel region from the lower side of the saddle-ridden type fuel cell vehicle. In order to realize such a mounting operation, the tank band is divided into an upper half portion and a lower half portion, and also the upper half portion is previously fixed between the upper frames and the lower frames and the lower haft portion is configured to be connectable to the upper half portion by fastener members. Upon a mounting operation of the fuel tank, after the fuel tank is mounted into the center tunnel region from the lower side of the saddle-ridden type fuel cell vehicle, the fuel tank is clamped by connecting the upper half portion and the lower half portion to each other by the fastener members while sandwiching the fuel tank between the upper half portion and the lower half portions, and then by tightening the fastener members. Thus, the fuel tank is fixed on the upper frames and the lower frames.
[Patent Document 1] Japanese Patent Application Publication No. 2010-269659A
However, upon a frontal or rear-end collision, a load is exerted on the saddle-ridden type fuel cell vehicle from a front or rear side thereof. As a result, the front wheel or the rear wheel is likely to be abnormally displaced rearward or forward, respectively. In particular, upon a rear-end collision, it is considered that the swingable arm together with the rear wheel is pressed forward and thus is excessively deformed forward to exceed a normal swing range about a pivot.
In the saddle-ridden type fuel cell vehicle described in Patent Document 1, the fuel tank and tank valve are arranged between the front wheel and the rear wheel, and the guard frame installed on bent portions of rear portions of the lower frames extends up to below the tank valve. Meanwhile, in the saddle-ridden type fuel cell vehicle, no frame is provided behind the tank valve arranged on the rear side of the tank valve. Thus, if the swingable arm and the rear wheel is excessively swung forward due to a frontal or rear-end collision, the swingable arm or the rear wheel hits against the guard frame so that an impact is absorbed and thus further swing thereof is blocked. However, if the swingable arm and the rear wheel are excessively deformed to exceed an anticipated range, the swingable arm or the rear wheel is likely to enter above the guard frame so that the swingable arm or the rear wheel can directly hit against the tank valve.
Also, when the swingable arm the rear wheel are excessively deformed forward due to a frontal or rear-end collision and thus directly hit against the tank valve, a load is exerted on the rear portion of the fuel tank via the tank valve. A direction of the load is varied depending on a direction, along which the swingable arm or the rear wheel directly hits against the tank valve or the like, and thus, for example, is likely to be a forward-oblique upward direction, a forward-oblique downward direction, a forward-oblique right direction or a forward-oblique left direction. Because the fuel tank is arranged so that the axis thereof is oriented in a front and rear horizontal direction, if a load is exerted on the rear portion of the fuel tank in a forward-oblique upward direction, a forward-oblique downward direction, a forward-oblique right direction or a forward-oblique left direction, the direction of the load corresponds to a direction intersecting the axis of the fuel tank. Due to having a generally cylindrical exterior shape and the like, the fuel tank is hardly deformed by a load exerted in a direction along the axis, but relatively easily deformed in a load exerted in a direction intersecting the axis. Accordingly, the load exerted in a direction intersecting the axis of the fuel tank is an unfavorable load to the fuel tank. Thus, if the swingable arm the rear wheel are excessively deformed forward due to a frontal or rear-end collision and thus directly hit against the tank valve, such an unfavorable load is likely to be exerted on the fuel tank. Therefore, it is desired to inhibit such a load in order to protect the fuel tank.
Further, there is a possibility that the upper frames are displaced due to an impact upon a frontal or rear-end collision and thus a positional relationship between the upper frame and the lower frames are changed. In this case, in the saddle-ridden type fuel cell vehicle described in Patent Document 1, the tank band (upper half portion) for fixing the fuel tank is fixed on both of the upper frames and the lower frames, and thus the tank band is easily deformed. If the tank band is deformed, a load is likely to be exerted on the fuel tank via the tank band. Accordingly, it is desired to inhibit such a load in order to protect the fuel tank.
Further, in the saddle-ridden type fuel cell vehicle described in Patent Document 1, there is a possibility that portions of the pair of right and left upper frames, which are positioned above the middle portion of the fuel tank in the front and rear direction, are deformed in directions approaching each other due to an impact upon a frontal or rear-end collision and thus a load is exerted on the fuel tank due to such deformation. Accordingly, it is desired to inhibit such a load in order to protect the fuel tank.
Meanwhile, in the saddle-ridden type fuel cell vehicle described in Patent Document 1, the fuel tank can be mounted in the center tunnel region by causing the fuel tank to pass between the pair of lower frames from the lower side of the vehicle. Accordingly, a diameter of the fuel tank has to be smaller than a dimension, in the right and left direction, of a space defined between the pair of lower frames. As a result, the diameter of the fuel tank is limited and thus it is difficult to increase a capacity of the fuel tank. In practice, because the fuel tank is mounted in the center tunnel region by causing the fuel tank to pass between the pair of lower frames after members such as brackets are attached on an outer periphery of the fuel tank, the diameter of the fuel tank needs to be set in consideration of dimensions of members such as brackets. Accordingly, the diameter of the fuel tank is further limited and thus it is further difficult to increase a capacity of the fuel tank.